"Er-lye" and its ilk was quite common, probably throughout England, certainly from the fen country (Bensusan) to the Midlands (my Mother - born 1910 near Nottingham - used to say "shore-lye" for surely, often, to emphasise it, in combination: "shore-lee, shore-lye". It's also found in Kipling, I think, so my earlier geographical constraint is possibly over-restrictive. And in many many folk songs.